There is a host adapter standard for a storage device according to the related art, such as a SATA storage device or a SAS storage device, on the assumption that the storage device has multiple ports. Therefore, a plurality of storage devices can be combined through one RAID controller to construct a storage array. It is preferable that a plurality of storage devices comply with (based on) a Peripheral Component Interconnect express (PCIe) standard be combined to form a storage array.